TM4SF19 and Arthritis: Treatment was initiated at disease onset with hLEL-Fc (human LEL region of Tm4sf19 fused to hIgG1, Fig. S3) or Etanercept (Enbrel, a human TNF receptor-IgG1 Fc fusion), a positive control for CIA treatment.23 To evaluate the therapeutic effect of hLEL-Fc, we administered the same 25 mg/kg dose of human LEL-Fc (hLEL-Fc) that was prophylactic with mouse LEL-Fc (mLEL-Fc) and a higher dose of 75 mg/kg, and found that the higher dose was significantly more effective in suppressing arthritis scores (Fig. 3a).